Diazotype material



United States Patent U.S. CI. 9691 11 Claims ABSTRACT OF THE DISCLOSUREDiazotype material of improved stability and light sensitivity isprovided through the use of p-phenylenediamine diazonium compounds whichare meta-substituted with alkoxy substituents and which additionallybear a hydroxyalkyl substituent in the p-amino group.

The present invention relates to a diazotype material and moreparticularly relates to improved photosensitive diazo components usefulin diazotype reproduction material.

In copying papers and other diazotype materials that have beensensitized with diazo compounds, the derivatives of unilaterallydiazotized p-phenylenediamine have been used as the photosensitivecomponents. These diazonium compounds have a tertiary amino group ofbasic character and they have been used successfully for both the dryprocess and the semiwet process.

For the dry process the diazo compounds which are most suitable arethose containing lower alkyl groups attached to the basic nitrogen atom,while for the semiwet process the best ones are those in which the basicnitrogen atom is attached to higher hydrocarbon radicals.

The substituents on the basic nitrogen atom affect not only couplingspeed, but they also affect the light sensitivity and keeping qualitiesof the diazo compounds and the light-sensitive layers preparedtherewith.

In considerable measure the properties of the p-aminobenzene diazocompounds depend also on substituents attached to the phenylene ring. Asubstituent such as a methyl, methoxy or carboxyl group in a positionortho to the diazonium group, brings about a considerable improvement instability and at the same time a color shift toward blue. Lightsensitivity is, however, lowered by these substituents. The presence ofan alkoxy group in a position meta to the diazonium group makes thediazo compound considerably more light sensitive in relation to theunsubstituted compound, but the keeping qualities become poorer as aresult. Despite their poor stability, this type of diazo compound isnevertheless important because of its high light sensitivity and itfinds practical use in cases where copies have to be prepared as quicklyas possible.

It has been found that the stability of this general type ofmeta-substituted diazonium compounds can be improved without loss oflight sensitivity through the use of heteroatom substituents in thealkoxy group in the position meta to the diazonium group. Some usefulimprovements in such diazonium compounds have been disclosed in relatedcopending U.S. patent applications owned by the assignee of the presentnivention. U.S. application Ser. No. 311,220, filed Sept. 24, 1963, nowU.S. Patent No. 3,272,630, describes a group of .alkoXy-, aryloxy-, andtertiary amino-substituted 3-alkoxydiazonium compounds. Application Ser.No. 414,878, filed Nov. 30, 1964, now U.S. Patent No. 3,280,246describes a group of alkylmercaptoand amino-substituted 3-alkoxy-3,462,271 Patented Aug. 19, 1969 "ice diazonium compounds. ApplicationSer. No. 425,921, filed Jan. 15, 1965, describes a group of alkoxy-,alkylmercaptoand amino-substituted 3-hydroxyalkoxydiazonium compounds.Application Ser. No. 547,721, filed May 5, 1966, describes a group ofquaternary aminosubstituted 3-alkoxydiazonium compounds.

Now, according to the present invention, there is provided diazotypematerial having improved stability and light sensitivity comprisingsubstituted p-aminobenzene diazonium compounds which aremeta-substituted with alkoxy, aryloxy, or aralkoxy groups andadditionally by hydroxyalkyl substituent in the p-amino group. Thelightsensitive diazonium compounds of the present invention have thegeneral formula:

wherein R is an alkylene group which contains at least 2 C-atoms, R isan alkylene group,

R is an alkyl, aralkyl, or hydroxyalkyl,

Z is an alkoxy, aralkoxy, aryloxy, or the group wherein R is hydrogen,or an alkyl or hydroxyalkyl,

R is alkyl, hydroxyalkyl, or aralkyl, or

R and R together with the nitrogen, for an unsubstituted or substituted5- or 6-membered heterocyclic group,

X is hydrogen or a halogen or a methyl group, and

Y is an anion of an acid.

The hydroxyalkyl radicals present in the diazo compounds defined above,including the hydroalkyl groups standing in some cases in place of thesymbols R R and R used in the general formula, are preferablymonohydroxyalkyl groups but may, however, also contain more than onehydroxyl group. Of the alkyl or .alkylene radicals, radicals with up tofour carbon atoms are preferred.

Where R and R are aralkyl groups, the benzyl group is preferred, whichmay optionally contain one or several low alkyl radicals or, on thenucleus, other substituents inert in the reaction.

The diazotype material according to the present invention exhibitsparticularly good stability with very good light sensitivity. The diazocompounds which characterize the material have good compatibility withadditives and stabilizers such as, e.g., citric acid, thiourea, zincchloride, naphthalene-1,3,6-trisulfonic acid. The material according tothe invention can be prepared both as two-component material for theso-called dry process and as onecomponent material for the so-calledsemiwet process. Preferably, there are used for the dry processtwocomponent material diazo compounds which at the amino group on thenucleus bear a low hydroxyalkyl radical besides a second such radical ora low alkyl radical and, for the semiwet process one-component material,diazo compounds which hear, at the amino group on the nucleus, at higheralkyl or hydroxyalkyl or aralkyl radical as a substituent in addition tothe hydroxyalkyl radical which is always necessary.

By the presence of hydroxyl groups at the alkali radicals which areattached to the amino group on the nucleus, solubility is increasedcompared with the compounds which have no hydroxyl group there.Moreover, the coupling dyes from the diazo compounds which arehydroxyalkylated at the amino nitrogen are, in general, not so sensitiveto changes in pH value, are more bluish, and in continuous tones are ofthe same color as in the full shades.

It is observed that it is not advantageous to use diazo compounds inwhich all alkyl groups are hydroxylated. Apart from the fact that thesolubility of the diazo compounds is so increased that they aredifficult to precipitate and their preparation is therefore attended bydifiiculties, the water fastness of the coupling dyes formed from thesecompounds is unsatisfactory.

The diazo compounds which characterize the reproduction materialaccording to the invention are new and are in general used as diazoniumchloride in the form of the double salts with metal halides, for examplezinc chloride or cadmium chloride. However, they may also be used inother precipitation forms, e.g., as sulfates, phosphates, borofluorides,for the preparation of the light-sensitive coatings.

Some of the present diazo compounds are shown in the table.

no-onn-rhomQ I IBOI'ZHOh-HOI 7 The preparation of the diazo compoundsaccording to the above general formula is effected according to methodsWhich are known in the literature and which are also stated in theabove-mentioned copending applications, but using for examplehydroxylated alkyl halides instead of alkyl halides for the alkylationof the amino group on the nucleus. It has, however, proved expedienttoefiect the introduction of the hydroxyalkyl group into the amino groupon the nucleus by alkylation with hydroxylated alkyl halides beforeintroducing a higher alkyl group or an aralkyl group. If the amino groupconcerned is already substituted with an alkyl or aralkyl group, thehydroxyalkyl group is best introduced with the aid of alkylene oxide,e.g., ethylene oxide or propylene oxide. Other methods of preparationmay also be effectively employed.

The present diazo compounds are used to prepare diazotype materials inthe usual manner as typically shown in the examples. Dry or semiwetdeveloping processes may be employed according to the material preparedand, depending upon the azo coupler components selected, dye images ofvarious colors may be rapidly formed.

EXAMPLE 1 Citric acid 0.50

g Sodium naphthalene-1,3,6-trisulfonate g 3.60 Saponin g 0.05Isopropanol cc 5.00

Zinc chloride double salt of the diazo compound from l-amino 4(hydroxyethylbenzyl)amino- 3-[fi-(methoxy)ethoxy] 6 chlorobenzene(Formula I) g 2.00

After drying, the sensitized base paper is imagewise exposed under atransparent original and developed with a solution which contains ineach 100 cc. of water:

Borax 2.5

Sodium carbonate 3.0 Sodium chloride 2.0

Thiourea 5.0 Sodium isopropylnaphthalene sulfonate 0.1 Resorcinol 0.6Phloroglucinol 0.6

High-contrast brown images on a white background are obtained.

If the base paper sensitized in the manner described above is treated,after exposure under an original, with a solution which contains in each100 cc. of water:

Phloroglucinol 0.330 Trisodium citrate 9.600 Sodium benzoate 2.420Adipic acid 1.975 Sodium chloride z 5.700 Sodium salt of adialkylnaphthalene sulfonic acid 0.200

neutral black images on a white background are obtained. Continuoustones are also of the same hue as the full shades.

Example 2 A photocopying base paper of the kind commonly used indiazotype processes and having a precoat consisting of colloidal silicicacid and polyvinyl acetate is coated on the precoated side with asolution which contains in 100 cc. of water:

G. Tartaric acid 10.0 Boric acid 3.0

Thiourea 2.5 7-hydr0xynaphthimidazole 2.0

Zinc chloride double salt of the diazo compound from l-amino 4(hydroxyethylbenzyl)amino- 3-[B-(methoxy)ethoxy] 6 chlorobenzene(Formula I) 1.93

After drying, the sensitized base paper is imagewise exposed under atransparent original and developed with ammonia. Bluish red lines on awhite background are obtained.

The foregoing examples have been presented for the purpose ofillustration and should not be taken to limit the scope of the presentinvention. It will be apparent that the described examples are capableof many variations and modificationsall such variations andmodifications are to be included within the scope of the presentinvention as set forth in the appended claims.

What is claimed is:

1. Diazotype reproduction material comprising a support and aphotosensitive composition coated thereon, said composition comprising aphotosensitive diazonium compound having the general formula:

HORr- YI-R:

l lzY wherein:

R is an alkylene group having 2 to 4 carbon atoms or abeta-hydroxypropylene group;

R is an alkylene group, having 2 to 4 carbon atoms;

R is an alkyl group having 1 to 3 carbon atoms, benzyl,

or hydroxyalkyl group;

Z is an alkoxy having 2 to 4 carbon atoms, phenoxy,

benzyloxy, or the group wherein R is an alkyl having 1 to 3 carbonatoms, or hydroxyalkyl group, and R is an alkyl having 1 to 3 carbonatoms, or benzyl;

X is hydrogen or a halogen or a methyl group; and

Y is an anion of an acid.

2. Material according to claim 1 wherein said diazonium composed is thezinc chloride double salt of 2-chloro-4-(N-hydroxyethyl-N-benzyl)amino-5 [beta (methoxy) ethoxy]benzenediazonium chloride.

3. Material according to claim 1 wherein said diazonium compound is thezinc chloride double salt of 2-chloro-4-(N-beta-hydroxypropyl-N-benzyl)-amino-5-[beta (methoxy)ethoxy]benzenediazonium chloride.

4. Material according to claim 1 wherein said diazonium compound is thezinc chloride double salt of 2-methyl-4-(N-hydroxyethyl-N-ethyl)amino-S-[delta-(N methyl N-benzylamino)butoxy]benzene diazonium chloride.

5. Material according to claim 1 wherein said diazonium compound is thezinc chloride double salt of 3-[beta- (butoxy)ethoxy]-4 (N-betahydroxybutyl N methyl) aminobenzene diazonium chloride.

6. Material according to claim 1 wherein said diazonium compound is thezinc chloride double salt of3-[gamma-(diethylamino)propoxy]-4-(N-hydroxyethyl N benzyl)aminobenzenediazonium chloride.

7. Material according to claim 1 wherein said diazoniurn compound is thezinc chloride double salt of 2-chloro- 4-(N-hydroxyethyl-N-hydroxyethylamino-S- [beta (phen0xy)ethoxy] benzene diazonium chloride.

8. Material according to claim 1 wherein said diazonium compound is thezinc chloride double salt of 3-[beta-(benzyloxy)ethoxy]-4-(N-hydroxyethyl N propyl)aminobenzene diazoniumchloride.

9. Material according to claim 1 wherein said diazonium compound is thecadmium chloride double salt of2-methyl-4-(N-hydroxyethyl-N-ethyl)amino-5-[ gamma (Nhydroxyethyl-N-propyl amino)propoxy]benzene diazonium chloride.

10. Material according to claim 1 wherein said diazonium compound is thezinc chloride double salt of 3-[betahydroxy-gamma-(N-diethylamino)propoxy] 4 (Nhydroxyethyl-N-ethyl)aminobenzene diazonium chloride.

11. Material according to claim 1 wherein said diazonium compound is thezinc chloride double salt of3-[betahydroxy-gamma-(N-diethylamino)propoxy] 4 (Nhydroxyethyl-N-benzyl)aminobenzcne diazonium chloride.

References Cited UNITED STATES PATENTS 2,529,464 11/1950 Von Glahn et al96-91 2,552,354 5/1951 Von Glahn et al 96-91 3,272,630 9/1966 Rauhut eta1. 9691 XR 3,281,246 10/1966 Rauhut et al 969l NORMAN G. TORCHIN,Primary Examiner C. BOWERS, Assistant Examiner US. Cl. X.R.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,462,271 August 19 1969 Herbert Rauhut et a1.

It is certified that error appears in the above identified patent andthat said Letters Patent are hereby corrected as shown below:

Column 1, line 71, "U. S. Patent No. 3,280,246" should read U. S. PatentNo. 3,281,246

Signed and sealed this 9th day of December 1969.

(SEAL) Attest:

Edward M. Fletcher, Jr. J

Attesting Officer Commissioner of Patents

